Combination shipping/display cartons are thoroughly described in the patent literature and commonly found throughout the packaging industry. For example, as early as 1926, M. Paruzzi patented a display carton that was formed from a single blank comprising both cut and perforated lines, (U.S. Pat. No. 1,609,186). Cartons were improved through the decades to provide for greater strength, easier conversion to display trays, and other features such as internal dividers or the ability to stack into store displays. Such shipping/display cartons may be constructed from single blanks or two or more blanks. Use of two separate blanks to form a carton requires alignment and gluing together of the blanks prior to erection of the final carton. Some single blanks have complex die-cut patterns with trapped cutouts that lead to waste/recycle, and such complex blanks require custom conversion machinery to erect. Some of the improvements claimed over the years are highlighted in the following discussion of the prior art.
U.S. Pat. No. 3,917,158 (Dorofachuk, et al.) claims a display carton formed from a single blank where the carton is convertible to a display tray by complete separation of the front panel, portions of the side panels and a portion of the rear panel. Conversion to the display tray requires separation along very long lines of perforations, leaving behind rough edges on the display tray.
U.S. Pat. No. 4,113,100 (Soja, et al.) claims a display carton formed from a foldable blank wherein tear strips are provided for separation of a cover member from the display tray member. The tear strip of the claimed carton circumscribes the entire circumference of the carton and must be removed in its entirety to separate the top portion from the bottom portion and render the bottom portion usable as a display tray.
U.S. Pat. No. 4,553,666 (Gullikson) claims a reinforced shipping/display carton that includes end flaps of doubled thickness. The separation of the upper portion from the display tray requires cutting around the carton along a demarcated “cut designating line,” followed by separation along two short perforated lines on the carton flaps.
U.S. Pat. No. 5,447,225 (Gunn, et al.) claims a tray/shroud shipping container where the shroud is removed from the lower tray by unlocking a number of tabs. The shroud telescopes within the tray and is locked in by the cooperation of tabs and small cut outs. However, it is suggested that the tray also be secured to the shroud with adhesive.
U.S. Pat. No. 5,715,993 (Pareike) claims a foldable carton formed from a single blank where the top cover portion is separable from the bottom tray portion by tearing off two short tear-strips, which are present on each of the inner side walls and accessible from the outside of the carton through cutouts or punch-outs on the outer tray walls. This carton seems to be of lightweight utility because the upper portion of the carton is only held to the tray by these small tear-strips. Furthermore, the tray portion of the carton will be left with these two cutouts on each side of the tray after separation of the upper portion, which may appear unsightly on a store shelf. Lastly, the upper edges of the display tray panels are not secured to any of the corresponding panels of the cover portion, meaning that the upper edges of the tray may be torn or damaged when the cartons are stacked for shipping if an adjacent carton catches on any of these unsecured tray edges.
A very similar carton to the Pareike carton ('993) is described by Laduranty in FR2713597. In this carton, tabs on each side of the carton are broken to separate the upper cover portion from the tray portion. Breaking of these tabs will leave unattractive tears on each side of the display tray.
U.S. Pat. No. 5,842,576 (Snow) claims a shipping/display carton formed from a single blank that is convertible to a display tray by simply lifting off the cover. However, there is nothing securing the front panel of the cover (the panel with the hand grip aperture) to the display tray portion, and it is presumed that tape or adhesive will be necessary to secure the front of the carton for shipping.
U.S. Pat. No. 6,510,982 (White, et al.) claims a shipper/display carton formed from a single blank that has weakened areas (i.e. perforation lines) running around each of the front, sides, and back panels. Although an aperture is provided for grasping the upper portion of the carton to tear it away, there must be some difficulty in breaking the carton along these long perforation lines.
U.S. Pat. Nos. 6,974,033 and 7,066,379 (McLeod, et al.) claim rugged shipper/display cartons, each formed from at least two separate blanks. The cartons include perforated lines around the cover portion such that the cover can be separated from the tray. However, each blank must first be separately erected, and then the cover telescoped into the tray with concomitant gluing.
Other examples of shipper/display cartons formed from single blanks that include either tear-strips and/or perforated lines are described in U.S. Pat. Nos. 7,175,066 and U.S Pat. No. 7,628,746 (Varanasi); U.S. Pat. No. 7,410,062 (Monk); U.S. Pat. No. 7,451,878 (Rochefort, et al.); and, U.S. Pat. No. 7,478,745 (Philips).
Perusal of the prior art shows that further improvements in the design of shipper/display cartons are warranted. The balance between strength, cost, ease of die-cutting the blank(s), ease in erecting the carton, and ease of opening the shipper/display carton at the point-of-purchase has not been achieved, in spite of decades of innovation in this area of packaging. Tear-strips have the clear disadvantage of leaving rough, unattractive edges on the display tray. Hiding the tear strips as two short strips behind access cutouts results in inadequate securing of the cover portion to the tray portion of the carton, in addition to unattractive tray panels. Nesting of separately erected tray and cover blanks in order to form cartons of improved shipping strength require gluing at the bottom edges of the covers and subsequent difficulty in separating the cover. Cartons with minimal attachment points between the cover and tray panels result in loose/bowed-out tray panels that may be torn or dented by adjacent cartons. Lastly, cartons with long perforation lines that run completely around the circumference of the carton invite cutting the use of a knife, and that may lead to damage of the product packages within the shipping carton.